Method of making ball bearings



o. H. LEHMANN METHOD OF MAKING BALL BEARINGS Dec. 18 ,1923.

Filed Sept. 2. 1922 WIT/#58358 OTI'Q HERMANN LEHMANN, OF LANCASTER, PENNSYLVANIA, ASSIGNOR TO THE BEARINGS. COMPANY OF AMERICA, OF LANCASTER, PENNSYLVANIA, A CORPORA 'IION OF NEW JERSEY.

METHOD MAKING BALL BEARINGS.

Application filed September 2, 1922. Serial No. 585,561.

To all whom it may concem: I I Be it known that I, Orro H.- LEHMANN, a citizen of the United States, residing at Lancastendn the State of Pennsylvania, have invented certain new and useful Improvements in Methods of Making Ball Bearings, of which the following is a specification, reference being had to the accompanying drawing hforming a rthereof. e object of t is invention is to rovide for the economical production of bal races for ball bearIngs, particularly of the type v known-as. angu ar contact radial bearings. In accordance with the invention both ball.

1 races are formedfrom a single disc of metal, which may be cut from a solid bar or stamped or forged. In one face of the blank a concentric oove of determined width is cut partway t rough the blank, usually halft way through, this out .being commonly known in the artas a trepanning cut. Then a similar groove, but of a different radius,

is cut from the other face of the disc far enough to meet the first cut. The inside di- 2 ameter of the cut of larger radius is preferably the same as the outside diameter of the cut of smaller radius. Then the smaller disc, separated from the outer ring thus formed is trepanned or drilled out concenso trically, leaving a ring of the required thickness. The two annular members thus formed are finished by turning, so as toform a proper cup or cone and arethen hardened and ground as usual. The invention will as be more fully explained hereafter with reference to the accompanying drawing in which it is illustrated and in which- Figure 1 is a view in perspective of the blank from which the raceways are formed. Figure 2 is a view' of the same in section after the first trepanning has been made.

Figure 3 is a similar view after the second trepanning has been made, the center member being shown in full perspective. I Figure 4 is a view in perspective of the center member after it has been trepanned or drilled out, the shaping of the inner race way to form the cone being indicated by broken lines.

Figure 5 is a view in section and perspective of the outer raceway, the she ping thereof to form the cup being indicated by broken lines.

Figure 6 is a view in section and perspective of the completed.- bearing, with. the

balls in position. 1

In the practice of the improved-method a disc or flat washer or blank a, of suitable diameter and thfckness is first prepared in any convenient manner, as by cutting from a solid bar or stamping-or forging. It is then subjected to a trepanning cut, as indieated at b in Figure 2, by which a concen tric groove is formed in one face of the disc part-way through the same, usually about calf-way throu h. A trepanning cut as indicated at c in Figure 3, is then made from the other face of the disc, forming a concentric groove which meets the groove 12. The. outer wall of the groove of: smaller radius, such as the groove 0, usually, but not necessarily registers with the inner wall ofthe other groove 6 so that the central por tion (2 is separated from the outer ring 6 r without further operation. BEy boring or otherwise, as indicated at e in igure 4, the central portion of the central member (Z is then removed and both annuli e and f are shaped by turning, as indicated by broken lines in Figures 4 and 5, to form the two raceways of the bearing, the two annuli be ing further finished by hardening and grinding as usual.

It will be observed that the improved method is practiced with a maximum of economy ofmaterial and ofoperations.

I claim as my invention: I

1. The method of making bail hearings which consists in providing a suitable blank, cutting a concentric groove from one face of the blank, cutting a concentric groove of difi'erent radius from the other face of the blank to meet the first out and thereby ionm ing two members of the bearing, and finish- "utting a concentric groovs from one face -of the blank. cutting a concentric groove of d'ficreni radius from the other face of the blank to meet the first cut, removing the central portion of the inner member thus formed and finishing the two ann'uli so formed.

This specification signed this 30th day of August, A. D. 1922.

()TTO HERMAN LEHM A NN. 

